Limiters are commonly used to protect power sensitive receiver components from external unwanted power sources such as radar, electronic warfare transmitters or from unwanted reflections within the operating system. Under normal operating conditions, the limiters offer low insertion loss thereby sustaining the receiver noise figure and linearity. When subjected to high-power signals, an impedance of the limiters is reduced to reflect the unwanted power away from the receiver.
Conventional limiters are restricted in power handling and scattering-parameter performance by a periphery parameter as related to the level of the input power applied. Large devices have a characteristic of high capacitance. Therefore, large devices increase the insertion loss of the limiter and noise figure of the system. When the devices are configured in an array to enhance the power handling capability, the resultant higher capacitance increases the insertion loss.
It would be desirable to implement an active field effect transistor limiter.